The case of ”genuine or fake of Dynastic Elder” started in T'ang Wen-tsung Tai-ho two years(828) and finished in Wen-tsung Kai-cheng four years(839), as long as the Wen-tsung's reigns. In this case, the emperor Wen-tsung attempted to enlarge the power of The Empress Dowager's political party. The Emperor combined the party with the Court Officials of Southern Offices to fight against the eunuch group. Simultaneously, the case reflected the wrestle between Military Commissioners and the eunuch group. The case seemed to be a simple relatives event. However, it is considered as the undercurrent of the historical development in the period of T'ang Wen-tsung. This case also presents the official scramble for judicial trial jurisdiction in the period of T'ang Wen-tsung. Wen-tsung issued an order allowing the Three Judicial Offices to try this case to fight against the Northern Prison Offices controlled by the eunuch group. This indicates another important significance of the case.